its original role as stateful, forms the basis of TypeEngine.Comparator. lots
of code goes back mostly as it was just with cleaner typing behavior, such
as simple flow in _binary_operate now.
declared on a single-table inheritance subclass
up to the parent class' table, when the parent
class is itself mapped to a join() or select()
statement, directly or via joined inheritane,
and not just a Table. [ticket:2549]
- [feature] Custom unary operators can now be
used by combining operators.custom_op() with
UnaryExpression().
- clean up the operator dispatch system and make it more consistent.
This does change the compiler contract for custom ops.
to select() construct, replaces columns inline
using the util.reduce_columns utility function
to remove equivalent columns. reduce_columns()
also adds "with_only_synonyms" to limit the
reduction just to those columns which have the same
name. The deprecated fold_equivalents() feature is
removed [ticket:1729].
- [feature] Added with_labels and
reduce_columns keyword arguments to
Query.subquery(), to provide two alternate
strategies for producing queries with uniquely-
named columns. [ticket:1729].
the operator precedence for the user-defined
operator, i.e. that granted using the ``op()``
method. Previously, the smallest precedence
was applied in all cases, now the default
precedence is zero, lower than all operators
except "comma" (such as, used in the argument
list of a ``func`` call) and "AS", and is
also customizable via the "precedence" argument
on the ``op()`` method. [ticket:2537]
which prevented referring to a CTE in a union
of itself without it being aliased.
CTEs now render uniquely
on name, rendering the outermost CTE of a given
name only - all other references are rendered
just as the name. This even includes other
CTE/SELECTs that refer to different versions
of the same CTE object, such as a SELECT
or a UNION ALL of that SELECT. We are
somewhat loosening the usual link between object
identity and lexical identity in this case.
A true name conflict between two unrelated
CTEs now raises an error.
- rework bindtemplate system of "numbered" params by applying
the numbers last, as we now need to generate these out of order
in some cases
- add positional assertion to assert_compile
- add new cte_positional collection to track bindparams generated
within cte visits; splice this onto the beginning of self.positiontup
at cte render time, [ticket:2521]
ForeignKeyConstraint, courtesy Ryan Kelly.
[ticket:2502]
- [feature] Added support for DELETE and UPDATE from
an alias of a table, which would assumedly
be related to itself elsewhere in the query,
courtesy Ryan Kelly. [ticket:2507]
- [feature] Added support for the Postgresql ONLY
keyword, which can appear corresponding to a
table in a SELECT, UPDATE, or DELETE statement.
The phrase is established using with_hint().
Courtesy Ryan Kelly [ticket:2506]
CheckConstraint, and PrimaryKeyConstraint will
attach themselves to their parent table automatically
when they refer to a Table-bound Column object directly
(i.e. not just string column name), and refer to
one and only one Table. Prior to 0.8 this behavior
occurred for UniqueConstraint and PrimaryKeyConstraint,
but not ForeignKeyConstraint or CheckConstraint.
[ticket:2410]
in result sets is now case sensitive by
default. SQLAlchemy for many years would
run a case-insensitive conversion on these values,
probably to alleviate early case sensitivity
issues with dialects like Oracle and
Firebird. These issues have been more cleanly
solved in more modern versions so the performance
hit of calling lower() on identifiers is removed.
The case insensitive comparisons can be re-enabled
by setting "case_insensitive=False" on
create_engine(). [ticket:2423]
.c. attribute of a select().apply_labels()
is now based on <tablename>_<colkey> instead
of <tablename>_<colname>, for those columns
that have a distinctly named .key.
[ticket:2397]
- resolved some serious speed hits I missed, we need to ensure
only deannotated columns are used in the local/remote collections and soforth
so that hash lookups against mapped columns don't dig into __eq__()
- fix some other parity mismatches regarding stuff from [ticket:2453],
including finding another case where _deep_annotate() was doing the wrong thing,
new tests.
- [feature] Major rewrite of relationship()
internals now allow join conditions which
include columns pointing to themselves
within composite foreign keys. A new
API for very specialized primaryjoin conditions
is added, allowing conditions based on
SQL functions, CAST, etc. to be handled
by placing the annotation functions
remote() and foreign() inline within the
expression when necessary. Previous recipes
using the semi-private _local_remote_pairs
approach can be upgraded to this new
approach. [ticket:1401]
requires that the updated table be present
in the FROM clause when an alias of that
table is also present in the FROM clause.
The updated table is now always present
in the FROM, when FROM is present
in the first place. Courtesy sayap.
[ticket:2468]
- [bug] Removed warning when Index is created
with no columns; while this might not be what
the user intended, it is a valid use case
as an Index could be a placeholder for just an
index of a certain name.
- mssql
- [feature] Added interim create_engine flag
supports_unicode_binds to PyODBC dialect,
to force whether or not the dialect
passes Python unicode literals to PyODBC
or not.
mechanics which could lead to incorrect
rendering of SELECT statements with aliases
and joins, particularly when using
column_property(). [ticket:2453]
column access on a row would raise
AttributeError with non-C version,
NoSuchColumnError with C version. Now
raises AttributeError in both cases.
[ticket:2398]
string format would not be applied to a
Numeric value returned as integer; this
affected primarily SQLite which does
not maintain numeric scale settings.
[ticket:2432]
condition with a "literal" in it would
raise an error on compile with certain
kinds of deeply nested expressions
which also needed to render the same
bound parameter name more than once.
[ticket:2425]
invokes common table expression support
from the Core (see below). [ticket:1859]
- [feature] Added support for SQL standard
common table expressions (CTE), allowing
SELECT objects as the CTE source (DML
not yet supported). This is invoked via
the cte() method on any select() construct.
[ticket:1859]
in the corresponding selectable to take into account clones
of the target column. fixes [ticket:2419]
- have _make_proxy() copy out the _is_clone_of attribute on the
new column so that even more corresponding_column() checks
work as expected for cloned elements.
- add a new test fixture so that mapped tests can be specified
using declarative.
Mike Bayer